CVE-2024-21871 is a vulnerability identified in the UEFI firmware of certain Intel processors, characterized by improper input validation that can be exploited by a privileged local user to escalate their privileges further. The UEFI (Unified Extensible Firmware Interface) is a critical low-level firmware interface responsible for initializing hardware and booting the operating system. Vulnerabilities at this level are particularly dangerous because they operate below the OS, potentially allowing attackers to bypass traditional security controls. This flaw requires the attacker to have local access and already possess high-level privileges, making exploitation complex and less likely remotely. However, successful exploitation can lead to full system compromise, affecting confidentiality, integrity, and availability by allowing unauthorized firmware modifications or persistent malware installation. The vulnerability has a CVSS 4.0 base score of 7.3, indicating high severity, with attack vector local, high attack complexity, and requiring privileges and user interaction. No public exploits or patches are currently available, but Intel has reserved the CVE and published the vulnerability details. This vulnerability is relevant for organizations using affected Intel processors with vulnerable UEFI firmware versions, particularly in environments where multiple users have privileged local access or where firmware integrity is critical.

For European organizations, the impact of CVE-2024-21871 can be significant, especially in sectors such as finance, government, critical infrastructure, and large enterprises that rely heavily on Intel-based hardware. An attacker exploiting this vulnerability could gain elevated privileges beyond their initial access level, potentially leading to unauthorized firmware modifications, persistent malware infections, or complete system compromise. This could result in data breaches, operational disruptions, and loss of trust. Since UEFI operates below the OS, traditional endpoint security solutions may not detect or prevent such attacks, increasing the risk. The requirement for local privileged access limits the attack surface but does not eliminate risk in environments with shared or multi-user systems, remote desktop services, or insider threats. The lack of known exploits in the wild currently reduces immediate risk but underscores the importance of proactive mitigation. The vulnerability could also affect supply chain security if compromised devices are distributed within European organizations.

1. Monitor Intel and OEM vendors closely for firmware updates addressing CVE-2024-21871 and apply patches promptly once available. 2. Restrict privileged local access to systems with vulnerable Intel processors to trusted personnel only, minimizing the risk of insider threats or unauthorized access. 3. Implement strict access controls and auditing on systems with multi-user environments to detect and prevent unauthorized privilege escalations. 4. Employ hardware-based security features such as Intel Boot Guard and Trusted Platform Module (TPM) to enhance firmware integrity verification and prevent unauthorized firmware modifications. 5. Use endpoint detection and response (EDR) solutions capable of monitoring firmware-level anomalies or unusual system behavior indicative of exploitation attempts. 6. Conduct regular security awareness training emphasizing the risks of local privilege misuse and the importance of reporting suspicious activity. 7. For critical infrastructure, consider network segmentation to isolate systems with vulnerable firmware from less secure network zones. 8. Maintain an inventory of affected hardware to prioritize patching and risk management efforts effectively.